Combined wipe and stretch forming machine with cross slide on the stretch forming assemblage



March 9, 1965 J. H. LEONARD 3,172,451

COMBINED WIPE AND STRETCH FORMING MACHINE WITH CROSS SLIDE ON THE STRETCH FORMING ASSEMBLAGE Filed Dec. 1. 1961 4 Sheets-Sheet 1 ATTORNE).

M arch 9,

Filed Dec.

H. LEONARD 3,172,451

J. COMBINED WIPE AND STRETCH FORMING MACHINE WITH QCSRQSS SLIDE ON THE STRETCH FORMING ASSEMBLAGE l, l l

4 Sheets-Sheet 2 March 1965 J. H. LEONARD 72,451

COMBINED WIPE AND STRETCH FORMING MACHINE WITH CROSS sums ON THE STRETCH FORMING ASSEMBLAGE Filed Dec. 1. 1961 4 Sheets-Sheet 3 II E l 2-1: ll

49 H75 4; 1 Q 9 y' 55] 52 I -s1- 20 i o 0 F i l 1H, 52 I 53 Hl' |I I t 59 k \\2I INVENTOR. 23

H L 58 I a I" 1. 9* 3e BY A 22 A 7' TORNEY March 9, 1965 J. H. LEONARD 3, 7

COMBINED WIPE AND STRETCH FORMING MACHINE WITH CROSS SLIDE ON THE STRETCH FORMING ASSEMBLAGE Filed Dec. 1. 1961 4 Sheets-Sheet 4 /55 50a 83 50 56\F 57 n- 2 [F C) 2 f 5/ j- 5a 51 8/ 85- so ;I a7 Mw\ o 01% INVENTOR. H 8 W78 H4 88: I d I '1 I BY 7 5 United States Patent 0 3 172 451 ooMnrNnn wire Ahlb s rnnrcn ronMrNo Mi CHINE WITH CROS SLIDE 0N THE STRETQH FGRMING ASSEMBLAGE John H. Leonard, Hudson, Uhio, assignor to The C yrri Bath Company, Solon, Shin, a corporation of Gino Filed Dec. 1, 1961, Ser. No. 1%,346 7 Claims. (ill. 72-16) This invention relates to combined wipe and stretch forming machines, and particularly to combined wipe and stretch forming machines such as disclosed in the United States Patent to Cyril I. Bath, Serial No. 2,514,830, issued July 11, 1950.

As therein described, stretch forming generally is accomplished by means of a turntable rotatable about an upright axis and supporting a side face die. One end of the stock is fixed for rotation with the die about the table axis. The other end of the stock is gripped by a stretch forming piston and cylinder assemblage which tensions the stock above the elastic limit during rotation of the table so that it is wrapped on the die.

The stretch forming piston and cylinder assemblage is swivelled about an upright axis offset from the axis of the turntable so that the line of pull of the stock through the swivelling axis of the stretch forming assemblage is tangential to the turntable at the instantaneous point of contact between the stock and the die.

For the combined Wipe and stretch forming, a wipe forming piston and cylinder assemblage is provided and is arranged to apply a wiping shoe to the stock on the side face of the die along the line of thrust directed generally through the axis of the turntable. However, in such case, the line of thrust of the wipe forming shoe frequently is not maintained through the instantaneous point of tangency and normal to the die face at that point.

In order to cause application of the wipe forming pressure more nearly at the instantaneous line of tangency of the stock at all times, a modification was made in the prior structure, as disclosed in U.S. Letters Patent No. 2,945,529, of Henry W. Hein, issued July 19, 1960. As therein disclosed, the stretch forming head is mounted on a carriage which moves along a guideway toward and away from the turntable. The head is carried on an arm which swivels about an upright axis. However, the guideway is olfset laterally of the turntable axis so that an upright plane through the swivelling axis of the stretch forming head and extending parallel to the guideway is at right angles to an upright plane through the turntable axis and in the normal line of thrust, of the wipe forming assemblage, passing through the axis of the turntable. As a result, the line of pull of the stock was more nearly at right angles to the line of thrust of the wipe forming shoe through the instantaneous point of tangency and at all times during the forming operation. This modification improved the operation, but the optimum relation cannot always be maintained, especially with dies of which the curvilinear side face was of different radii at different portions along its length.

In accordance with the present invention, the arrangement disclosed in U.S. Patent No. 2,945,529 is further modified to approach the optimum relation wherein the line of pull through the swivel axis of the head and in stantaneous point of tangency is at a right angle to the line of thrust of the wipe shoe when applied at the point of tangency. For this purpose, the stretch forming ice head is mounted on a cross slide which is mounted, in turn, on a carriage movable toward and away from the table along such an offset guideway as disclosed in US. Patent No. 2,945,529. Thus the head can be moved transversely of the path of the carriage in all positions of the carriage. By proper manipulation of the cross slide, the stock can be maintained at all times exactly at right angles to the line of thrust of the Wipe forming shoe through the instantaneous line of tangency. This improved type of structure is particularly desirable for use in combined stretch and wipe forming of the light weight stock on relatively heavy machines wherein the stress imposed on the stock for swinging the stretch forming head about its upright swivelling axis might unduly increase the tension applied.

Various other objects and advantages of the present invention will become apparent from the following description wherein reference is made to the drawings, in which:

FIG. 1 is a top plan view of an apparatus embodying the principles of the present invention;

FIG. 2 is a front elevation of the apparatus illustrated in FIG. 1;

FIG. 3 is a fragmentary left end elevation of the apparatus illustrated in FIG. 1;

FIG. 4 is an enlarged top plan view of the stretch forming carriage and cross slide of the present invention;

FIG. 5 is an enlarged side elevation of the structure illustrated in FIG. 4;

FIG. 6 is a sectional view of the stretch forming carriage, and is taken on the line 6-6 in FIGS. 4 and 5, part thereof being shown in elevation for clearness in illustration;

FIG. 7 is a schematic drawing showing the hydraulic circuit and electric control means of the machine;

FIG. 8 is a wiring diagram showing a control circuit for the cross slide; and

FIG. 9 is a fragmentary view of the stretch head and support of FIG, 7, showing a modification thereof.

Referring specifically to the drawings, the machine comprises a horizontal frame 1 on which a turntable 2 is mounted on a suitable pivot post 3 for rotation about an upright axis. The table carries a concentric ring gear 4 which is engaged by a pinion gear 5 on the output or driven shaft 6 of a secondary gear reducer 7. The secondary gear reducer is driven, in turn, by a primary gear reducer 8, which is driven by a pair of variable speed reversible hydraulic motors 9. The motors are settable hydraulically by control valves 9a. Operating fluid pressure is supplied to the machine by a pump It} driven by an electric motor 11.

The frame has an elongated portion 12 which comprises essentially a pair of girders 13 arranged in fixed and laterally spaced face to face relation to each other on suitable crosstie members 14. Mounted on the frame are suitable parallel upper trackways i6 and lower trackways 17. Between the level of these trackways are thrust rails 18 which also act as holddown trackways. Mounted on the trackways is a carriage, indicated generally at 29, having front wheels 21 which ride on the trackway 16 and rear Wheels 22 which normally ride on the track- Way 17. The carriage is also provided with thrust rollers 23 which engage the inner faces of the rails 18 and thus cooperate in maintaining the carriage in proper alignment with the tracltways free from binding stresses due to cocking of the carriage under tension forces applied in a direction toward the table but at a point offset laterally of the trackways.

Since the stretch forming head is mounted on the carriage 20 above the level of the trackways, there is a tendency for the carriage to tilt about the front wheels 21. Accordingly, the wheels 22 are arranged so that they engage the underside of the rails 18 upon the slight forward tilting :of the carriage 20, and thus prevent further tilting of the carriage.

For applying yieldable tension to the carriage for yieldably resisting its movement along the trackway while tensioning the stock to be formed, stretch forming power means are provided. These comprise a piston and cylinder assemblage 30, including a cylinder 31 in which is a double-end piston 32 having hollow piston rods 33. The outer ends of the rods are connected to opposite ends of the frame of the machine, respectively. Pressure fluid from the pump is supplied through suitable reversing valves, later described, to the out ends of the rod 33, which are hollow and provided with suitable ports so that pressure fluid can be introduced to either side of the piston selectively, and vented fromthe opposite side.

The operation of the carriage thus far described is fully set forth in application Serial No. 860,796, filed December 21, 1959, issued as Patent No. 3,017,916 to Pius J. Nasvytis, and entitled Stretch Forming Machine With Trolley Supplied Power on Stretch Carriage.

As described in the above copending application, the cylinder 31 extends lengthwise of the tracks and is secured to the carriage 20 for movement therewith endwise of the trackways. However, stresses and forces on the carriage may cause slight cocking or shifting of the carriage relative to a straight path. The cylinder 31 is connected to the carriage 20 by a swivel connection so that it can maintain its proper position with its axis coincident with the axes of the piston rods during travel of the carriage along the trackways.

For this purpose, suitable links 35 are connected to the carriage 20 by pivots 36 for rocking about a horizontal axis extending transversely of the carriage and trackways. The opposite ends of the links are connected by ball and socket connections 37 to a housing 38 which is fixedly mounted on the cylinder. The housing 38, in turn, is provided with rollers 39 which ride on trackways 40 carried on a center portion 41 of the frame of the machine.

Mounted on the carriage is a pump and electric motor unit 43 by which fluid pressure may be supplied to the stretch head for operating the gripping jaws thereof, all in a well known manner.

Referring next to the part of the structure with which the present invention is particularly concerned, movable means in the form of a cross slide 49 are mounted on the carriage 20 and a stretch head, indicated generally at 50, which is adapted to grip one end of the stock, is connected by an upright pivot 50a to a rigid support or to the arm 51 on, and forming part of, the cross slide. The arm 51 is mounted on slides 52 which are arranged to engage cooperative slideways 53 on the carriage 20. The slideways 53 extend in a horizontal plane transversely of the trackways or path of the carriage 2t) and preferably are of such length that by sliding the cross slide along them transversely of the carriage, the longitudinal axis of the arm 51, and hence the head 50, can be disposed to move the gripped stock from a position in a vertical plane through the turntable axis and parallel to the trackways or path of the carriage 20 outwardly to and beyond a parallel upright plane tangent to the outer periphery of the turntable.

In order to move the cross slide 49 transversely of the carriage 20 and thereby move the head transversely of the path of the carriage 20, a suitable additional power means in the form of a double end piston and cylinder assemblage 55 is provided. The assemblage 55 includes a cylinder 56 fixedly mounted on the arm 51 and extending parallel to the slideways 53. A piston 57 is reciprocable in the cylinder and is provided with rods 58, the ends of which are connected in suitable brackets 59, respectively, which are rigid with the carriage 28. The rods are hollow and connected to a hydraulic circuit and have ports near the piston 57 so that the assemblage can be reversed in operation.

To move the cross slide 49, and hence the head 50, transversely of the trackways 16, 17, and 18, or path of the carriage 20, in any position of the carriage 28 along the trackways, pressure fluid can be supplied through the rods 58 to one side or the other of the piston 57, selectively, and the cylinder 56 vented at the opposite side. Further, both ends of the cylinder may be hydraulically locked so as to maintain the cross slide fixedly in any position desired along the slides 53.

The Wipe forming assemblage, indicated generally at 60, comprises a wipe shoe 61 mounted on a pedestal 62 of a slide 63. The slide is mounted on a carriage 64 for sliding toward and away from the table. 'Also mounted on the carriage .is a piston and cylinder assemblage, indi cated generally at 65. The assemblage includes a piston 66 reciprocable in a reversible cylinder 67 and having a piston rod 68 connected to the pedestal 62. The carriage 64 is slidable along suitable trackways 67 by means of a reversible piston and cylinder assemblage 68. This assemblage comprises a cylinder 69 mountedon the carriage for movement therewith, and a double end piston '76 having rods 71 fixedly connected at their ends to the frame of the machine. Pressure fluid is supplied toeither face of the piston 70, and the cylinder is vented at the opposite face, selectively, by means of a solenoid operated valve 72. Thus, the wipe shoe can be traversed parallel to the trackways 16.

As a result of this traversing, it sometimes happens that the point of application of the wipe shoe against the side face of the die is not through the axis of the turntable. However, it is desirable that the line of, application of wiping force intersect the die face at the instantaneous point of tangency and, concurrently, that the angle between the line of application of the force of the wipe shoe and the line of pull of the stock A be maintained at 90, as near as may be, so that the wiping takes place at the instantaneous point of tangency at all times. The advantages of olfsetting the carriagelil outwardly toward the periphery of the table on offset trackways 16, as described in the above patent, are supplemented in the present-invention by moving the head 50 transversely of the carriage 20 by power means so as to maintain the line of pull of stock at right angles to the line of thrust of the wipe shoe at the instantaneous point of tangency. This is done by shifting the arm 51, as a whole, transversely of the track while the arm remains parallel to its original position.

The carriage 20 may be operated for engaging and tensioning the stock, selectively, by introducing the pressure fluid through the appropriate piston rod 33, and venting the appropriate end of the cylinder 31 by means of a suitable reversing valve 75, which may he solenoid operated, and to which pressure is supplied through the pump 10.

In. order to reciprocate the cross slide 49 and arm 51 transversely of the trackways 16 along the slideways 53, pressure fluid from the pump 10 is supplied through a suitable reversing valve 76, operable by solenoids 77 and 78. An overload relief valve 79 is interposed between the valve 76 and the pump 10. The valve 76 is, connected to opposite ends of the piston rod 58 by means of lines 80 and 81, respectively. By operation of the valve 76, the cross slide 49 and arm 51, and thereby the stretch head 49, may be moved to different positions transversely of the track,- ways 16.

In order to make the movement of the cross slide responsive to the angularity of the. stock S relative to the trackways 16, switch means in the form of contact bars 83 and 84 are mounted on the arm 51 at opposite sides of the head, respectively, so that they can be engaged and thereby operated by the head as it is swung about its pivot 50a to one side or the other of an intermediate position in which the unwrapped portion of the stock is along the longitudinal axis of the arm and parallel to the path of the carriage 20. These contact bars are positioned close to the head so that a very slight movement of the head about the pivot 50a causes contact with one bar or the other. The contact bars are connected in a circuit by wires 85 and 86, respectively, to traversing relays 87 and 88. As illustrated in FIG. 7, the relays are connected in a 12-volt circuit to which power is supplied from a suitable transformer 89. The arm 51, head 50, and pivot 50a are all grounded to the frame of the machine and the frame is connected to one side of the circuit.

As illustrated in FIG. 8, the solenoid 77 is connected in series between contacts 870 of the relay 87. The solenoid 78 is connected in series between the contacts 880 of the relay 88. Assuming the head 50in FIG. 7 is arranged so that the line of pull on the stock S is parallel to the trackways 16 of the carriage 20, either contact bar 83 or 84 is in contact with the head. If, however, the head swings counterclockwise, it makes contact with the bar 83, thus energizing the relay 87 which closes the normally open contacts to the solenoid 77. This introduces pressure fluid to the assemblage 55 so that the cross slide moves away from the contact bar 83-. When contact is thereby broken, the solenoid 77 is deenergized, but the valve 76 is restored to its normal position in which the assemblage 55 is hydraulically locked. On the other hand, if the head is swung clockwise so as to make contact with the bar 84, the relay 88 is energized, thus closing its contacts 88c and connecting the solenoid 78 to the 12-volt circuit. This energizes the solenoid 78, thus setting the valve '76 to cause the pressure fluid to be admitted to the assemblage 55 for moving the cross slide in a direction so that the head breaks contact with the bar 84, or in the up direction, in FIG. 7. Thus any slight deviation of the line of pull of unwrapped portion of the stock from parallelism with the trackways 16, or path of the carriage 20, and thus out of right angle relation to the line of thrust of the wiping by the shoe 61 through the instantaneous point of tangency, is corrected by the shifting of the head 50 transversely of the trackway 16. Thus by the relatively simple circuit and arrangement shown, the optimum in angularity between the stock and the direction of thrust of the wipe shoe through the line of tangency can be approached effectively.

If desired, as illustrated in FIG. 9, a stretch head 98, corresponding to the head 50, may be secured in fixed position on a rigid arm 91, corresponding to the arm 51. Since the head 98 does not swing about an upright axis, switch means in the form of contact bars 2 and 93 having contacts 94 and 95 are provided. A shift in angularity of the unwrapped stock from an intermediate position causes the stock to engage one or the other of the contacts to complete a circuit, depending on the direction of the shift.

Having thus described my invention, I claim:

1. A stretch forming machine comprising a frame, a turntable mounted thereon for rotation about an upright axis, a side face die on, and rotatable with, the turntable, means for securing one end of a length of stock in fixed position relative to the die, a carriage mounted on the frame for movement along the horizontal path toward and away from the turntable, stretch forming power means for yieldably urging the carriage away from the turntable, a stretch forming head adapted to grip the other end of the stock, movable supporting means connecting the head to the carriage for movement of the head with the carriage along said path toward and away from the table and for concurrent movement of the head relative to the carriage transversely of said path in all positions of the carriage along the path, additional power means operable in all positions of the carriage along said path for moving said movable means transversely of said path, table driving power means for rotating the table for wrapping the stock on the side face of the die while the stock is held under tension, said movable means comprising a cross slide on the carriage and guided thereby for horizontal movement at a right angle to said path of the carriage, and said additional power means being mounted on the carriage and drivingly connected to the cross slide.

2. A machine according to claim 1 wherein said cross slide includes a rigid supporting portion, and said head is pivotally connected to said supporting portion.

3. A machine according to claim 1 wherein control means are provided for rendering the additional power means operative to move the movable supporting means in opposite directions, selectively, transversely of the path, and means responsive to changes in the angularity between the unwrapped portion of the stock and the path of the carriage for rendering the control means operative to cause the movable supporting means to move the head transversely of said path in directions to cause the unwrapped portion of the stock to approach parallelism with said path.

4. A stretch forming machine comprising a frame, a turntable mounted thereon for rotation about an upright axis, a side face die on, and rotatable with, the turntable, means for securing one end of a length of stock in fixed position relative to the die, a carriage mounted on the frame for movement along the horizontal path toward and away from the turntable, stretch forming power means for yieldably urging the carriage away from the turntable, a stretch forming head adapted to grip the other end of the stock, movable supporting means connecting the head to the carriage for movement of the head with the carriage along said carriage path toward and away from the table and for concurrent movement of the head relative to the carriage transversely of said path in all positions of the carriage along the path, additional power means operable in all positions of the carriage along said path for moving said movable means transversely of said carriage path, table driving power means for rotating the table for wrapping the stock on the side face of the die while the stock is held under tension, control means for rendering the additional power means operative to move the movable supporting means in opposite directions, selectively, transversely of the path of the carriage, and sensing means responsive to changes in the angularity between the unwrapped portion of the stock and the path of the carriage for rendering the control means operative to cause the movable supporting means to move the head transversely of said path in directions to cause the unwrapped portion of the stock to approach parallelism with said path of the carriage.

5. A machine according to claim 4 wherein said control means includes two electric circuits, means rendered operative by one circuit when that circuit is energized to cause the additional power means to move the movable supporting means in one direction transversely of said path, and operative when the other circuit is energized to cause the additional power means to move the movable supporting means in the opposite direction transversely of said path, and switch means rendered operative to connect the circuits to a source of electric power, selectively, by, and dependent upon, changes in the angularity of the unwrapped stock and said path.

6. A machine according to claim 4 wherein the switch means includes contact means for each circuit and which are normally open when the unwrapped stock is parallel to said path, and the contact means of one circuit become closed when the unwrapped stock becomes slightly bias to a plane parallel to said path at one side of the plane, and the contact means of the other cirrcuit become closed when the unwrapped stock becomes slightly bias to said plane at the other side of the plane, and each circuit renders the control operative to move the movable means transversely of said path in the direction to open the then lated to the head so that one is closedby swinging the head closed contact means. in one direction from said position and the other is closed 7. A machine according to claim 4 wherein the head by swinging the head in the opposite direction from said is mounted on the movable means for swinging relative position.

thereto about an upright pivotal axis, and each of said 5 References Cited in the file of this patent switch means are opened and closed by swinging of the head about its pivotal axis in opposite directions from a UNITED STATES PATENTS given intermediate position, said switch means being re- 3 016 32 De Marco Jam 16, 1962 

1. A STRETCH FORMING MACHINE COMPRISING A FRAME, A TURNTABLE MOUNTED THEREON FOR ROTATION ABOUT AN UPRIGHT AXIS, A SIDE FACE DIE ON, AND ROTATABLY WITH, THE TURNTABLE, MEANS FOR SECURING ONE END OF A LENGTH OF STOCK IN FIXED POSITION RELATIVE TO THE DIE, A CARRIAGE MOUNTED ON THE FRAME FOR MOVEMENT ALONG THE HORIZONTAL PATH TOWARD AND AWAY FROM THE TURNTABLE, STRETCH FORMING POWER MEANS FOR YIELDABLY URGING THE CARRIAGE AWAY FROM THE TURNTABLE, A STRETCH FORMING HEAD ADAPTED TO GRIP THE OTHER END OF THE STOCK, MOVABLE SUPPORTING MEANS CONNECTING THE HEAD TO THE CARRIAGE FOR MOVEMENT OF THE HEAD WITH THE CARRIAGE ALONG SAID PATH TOWARD AND AWAY FROM THE TABLE AND FOR CONCURRENT MOVEMENT OF THE HEAD RELATIVE TO THE CARRIAGE TRANSVERSELY OF SAID PATH IN ALL POSITIONS OF THE CARRIAGE ALONG THE PATH, ADDITIONAL POWER MEANS OPERABLE IN ALL POSITIONS OF THE CARRIAGE ALONG SAID PATH FOR MOVING SAID MOVABLE MEANS TRANSVERSELY OF SAID PATH, TABLE DRIVING POWER MEANS FOR ROTATING THE TABLE FOR WRAPPING THE STOCK ON THE SIDE FACE OF THE DIE WHILE THE STOCK IS HELD UNDER TENSION, SAID MOVABLE MEANS COMPRISING A CROSS SLIDE ON THE CARRIAGE AND GUIDED THEREBY FOR HORIZONTAL MOVEMENT AT A RIGHT ANGLE TO SAID PATH OF THE CARRIAGE, AND SAID ADDITIONAL POWER MEANS BEING MOUNTED ON THE CARRIAGE AND DRIVINGLY CONNECTED TO THE CROSS SLIDE. 